The present invention relates to the loading (or downloading) of files from a client to a target server. It relates more particularly to the loading of applications to servers on board an air transport means.
Methods of loading files to so-called avionics servers, that is, servers used in the context of operation of an air transport means such as an airplane, are currently known. They are based on protocols specifically created for this usage.
FIG. 1 illustrates a file load mode according to such a method of the prior art. A set of files 1 has to be loaded from a client to an avionics type server 5 among a plurality of servers 5-6 of a group 4. The files 1 are, for example, the set of files needed to install and run a computer application, that is, for example, data files, binary files and associated configuration files.
The files 1 are organized to conform to a predetermined format. This format is typically the one defined in the ARINC 665 standard, as drawn up and published by the AEEC (Airlines Electronic Engineering Committee). This format mainly comprises the files to be loaded themselves, and a header listing the different files to be loaded and including various additional simple information, such as a data integrity check field, in the form of a cyclic redundancy code, or CRC (see section 4.0 of ARINC report 665) and a unique identifier commonly called PN or “Part Number” (see section 2.1 of ARINC report 665).
The set of data 2 obtained after formatting the files 1 is then made available to a client 3, for example by reading, on the client, a computer medium on which the set of data 2 has been stored. The client 3 concerned is, for example, an application, that is, a computer program, running on a machine and dedicated to the loading of data to avionics servers. It is often designated DLCS (“Data Loading and Configuration System”). It is further designed to offer a man-machine interface, enabling in particular a user to control a load.
Then, the DLCS client 3 loads the set of data 2 in the ARINC 665 format to a server 5 chosen from the group of avionics servers 5-6 of the group 4. To do this, a specific communication protocol is used between the client 3 and the server 5: this is the ARINC 615A protocol which is also the subject of a report drawn up and published by the AEEC standardization organization.
According to the ARINC 615A protocol, the DLCS 3 transmits the header of the data set 2 to the server 5 which is the load target. The server 5 then analyzes this header and deduces from it the list of files to be loaded. The files contained in the data set 2 in the ARINC 665 format are then loaded to the server 5 which checks their integrity using the corresponding check field included in the header transmitted previously. In this communication mode, the target, that is, the server 5, is by turns client and server, since it requires the loading of the different files based on the list of files available to it. Similarly, the client can become file server, which precludes the use of light clients. This mode of operation also makes communication clumsy and relatively slow.
Furthermore, the interchanges between the DLCS 3 and the server 5 carried out according to the ARINC 615A communication protocol use TFTP (Trivial File Transfer Protocol) as the transfer protocol (see ARINC report 615A, section 5.3.2). The TFTP is in particular described in the technical specification RFC 1350, published in July 1992 by the IETF (Internet Engineering Task Force). The use of this transfer protocol also contributes to making the interchanges between the DLCS 3 and the server 5 relatively slow.
In addition to the loading of files to avionics servers, in particular for setting up dedicated applications, it may be advantageous to load files to other types of servers, also on board but not specific to the avionics domain, for example standard application servers (Web servers, for example). Such file loads could thus be used to set up new services in air transport.
Now, the use of a loading method used in an avionics context, such as that described above with reference to FIG. 1, would not be satisfactory for a number of reasons in such a context. First of all, the standard servers sold commercially are not suited to the use of avionics protocols, in particular the ARINC 615A protocol. Furthermore, even if these servers were upgraded to support the ARINC 615A communication protocol, the situation would not be ideal since ARINC 615A is designed for small file transfers occurring in an environment that is already more than adequately secure, which is not always the case for non-dedicated applications.
Moreover, there is no standard protocol for loading data outside the avionics-specific context, that is, in what is often called the “open world”. In practice, there are multiple communication protocols between two communication entities, and a multitude of different file formats and a large number of transfer and transport protocols (HTTP, FTP, UDP, etc). This makes it very difficult to provide a uniform load solution.
Furthermore, the use of “open world” file formats does not allow compatibility with the loading tools used in the avionics sector, so it would be necessary to have two ranges of loading tools: a first for loading specific applications to avionics servers and a second for loading non-dedicated applications to standard servers.
Moreover, a file load to an onboard server according to an “open world” protocol raises problems of security, since it does not guarantee the authenticity of the files loaded, or the consistency of the files in the case of simultaneous loads to one and the same target.
One object of the present invention is to overcome the abovementioned problems.
Another object of the invention is to enable a fast, secure and authenticated file load to standard servers, where appropriate followed by the installation of an application from the loaded files.
Yet another object of the invention is to preserve a degree of compatibility with the loading tools used in the avionics sector.